Storage subsystems or storage apparatuses that employ disk drives etc., as the storage devices are known. When data input/output processing against the storage devices is controlled the disk head is aligned.
For example, according to PTL1, a volume configured of storage devices includes one or more tracks. In a real storage area of the storage device there are a control information part in a top of the track (home address, record 0) and a data part (record 1, record 2, . . . ) behind the control information part. If a mainframe (MF) host computer issues a request to a storage controller to read or write a track, the storage controller reads the track from the disk in accordance with a read command or write command, reads the value of the track control information part (home address), confirms the track position information, and executes read or write access to the data part after confirming that a head alignment has correctly been completed against the track.